Multiple output anesthesia system

ABSTRACT

The present invention provides improved anesthesia delivery systems that consistently and reliably deliver anesthesia gas to multiple gas outlets. The systems are particularly useful for anesthetizing multiple mammals and living specimens to be imaged by a low-light level imaging system. The anesthesia delivery systems are suitable for use with conventional oxygen sources, and convert the high pressures associated with a conventional oxygen source to lower pressures suitable for use with small mammals and suitable for combination with an anesthesia gas at low flow rates. The systems include an anesthesia gas source that combines anesthesia gas with the oxygen. The combination of anesthesia gas and oxygen is supplied to one or more multiple outlets.

FIELD OF THE INVENTION

[0001] The present invention relates generally to anesthesia deliverysystems. In particular, the present invention relates to anesthesiasystems for use with living specimen imaging applications.

BACKGROUND OF THE INVENTION

[0002] One new and specialized type of imaging involves the capture oflow intensity light—often on the order of only tens to hundreds ofphotons—from a light-emitting sample. The low intensity light source maybe emitted from any of a variety of light-emitting sources within aliving specimen, e.g., luciferase expressing cells within a mammalianspecimen. The source of the light indicates portions of the sample, suchas traced molecules in a particular portion of a laboratory mouse, wherean activity of interest may be taking place. Some specialized in-vivoimaging applications may include analysis of one or more representationsof emissions from internal portions of a specimen superimposed on aphotographic representation of the specimen. The photographicrepresentation provides the user with a pictorial reference of thespecimen. The luminescence representation indicates portions of thespecimen where an activity of interest may be taking place.

[0003] Obtaining the luminescence representation may involve imagecapture over an extended period of time, e.g., minutes. The livingspecimen is typically anesthetized during this time to prevent movementthat may compromise image capture. Current imaging systems employanesthesia delivery systems that do not consistently and reliablyanesthetize specimens or deliver anesthesia gases. These conventionalsystems are miniaturized relatives of anesthesia systems used inhospitals and the like. Systems of this nature are designed for a singlerecipient. However, many imaging systems as described above may requiregas delivery to multiple small mammals. So far, scaling to multiplerecipients, and via lower flow rates associated with the smallerrecipients has been largely unsuccessful.

[0004] More specifically, the conventional anesthesia delivery systemsrely on a single general upstream flow control for the entire deliverysystem and downstream on/off switches for each outlet. The result is ananesthesia system that does not reliably deliver gas to each outlet.Commonly, anesthesia gas does not arrive at each interface with aconsistent pressure or flow rate. For example, when one outlet is turnedon/off, the remaining interconnected outlets do not maintain consistentgas output. As a result, anesthesia gas for one or more of the mammalsmay be interrupted, fluctuate dramatically—or significantly diminished.Insufficient anesthesia gas supply may result in unintentionalconsciousness for a mammal, and unexpected locomotion that compromisesimaging.

[0005] In view of the foregoing, improved anesthesia delivery systemswould be desirable.

SUMMARY OF THE INVENTION

[0006] The present invention relates to improved anesthesia deliverysystems that consistently and reliably deliver anesthesia gas tomultiple gas outlets. The systems are particularly useful foranesthetizing multiple mammals and living specimens to be imaged by alow-light level imaging system. The anesthesia delivery systems aresuitable for use with conventional oxygen sources, and convert the highpressures associated with a conventional oxygen source to lowerpressures suitable for use with small mammals and suitable forcombination with an anesthesia gas at low flow rates. The systemsinclude an anesthesia gas source that combines anesthesia gas with theoxygen. The combination of anesthesia gas and oxygen is supplied to oneor more multiple outlets.

[0007] One outlet of the anesthesia delivery system may lead to aninduction chamber used to sedate a living specimen, prior to insertionin an imaging box or chamber. Another outlet may lead to a manifold orgas delivery device having multiple specimen interfaces, each of whichis capable providing anesthesia gas to a specimen associated therewith.The manifold or gas delivery device may be placed within the imaging boxor chamber and used to maintain a sedated state of the specimen. In oneembodiment, the induction chamber includes a scavenger system to collectanesthesia gas that escapes from the induction chamber. In anotherembodiment, the gas delivery device includes a scavenger system thatcollects anesthesia gas locally, which is advantageous when the gasdelivery device is employed in an imaging box for extended periods.

[0008] The present invention may also provide independent control ofgases to each of the multiple outlets, thereby enabling reliable gasflow to each gas outlet. This is in contrast to prior art systemscomprising general flow control and binary on/off switches for eachoutlet that do not reliably allow controlled flow to each outlet. In aspecific embodiment, the present invention includes a dedicatedflowmeter and flow control disposed between an anesthesia source andeach gas output.

[0009] In one aspect, the present invention relates to a gas deliverysystem capable of delivering an anesthesia gas to a plurality of gasoutlets. The gas delivery comprises an oxygen inlet that receives oxygenfrom an oxygen source. The gas delivery system also comprises a pressureregulator having an inlet that receives oxygen from the oxygen inlet andhaving an outlet that provides oxygen at a lower pressure. The gasdelivery system further comprises an anesthesia gas source having aninlet coupled to receive low-pressure oxygen from the outlet of thepressure regulator and capable of adding anesthesia gas to thelow-pressure oxygen. The gas delivery also comprises a first gasdelivery outlet coupled to a gas delivery device having one or moreliving specimen interfaces and capable of providing anesthesia gas andoxygen to the one or more living specimen interfaces. The gas deliveryfurther comprises a second gas delivery outlet coupled to an inductionchamber and capable of providing anesthesia gas and oxygen to theinduction chamber.

[0010] In another aspect, the present invention relates to an imagingsystem for capturing an image of a living specimen with a camera. Theimaging system comprises an imaging box having a set of walls enclosingan interior cavity and a camera mount configured to position the camerarelative the interior cavity. The imaging system also comprises a gasdelivery system. The gas delivery system comprises an oxygen inlet thatreceives oxygen from an oxygen source. The gas delivery system furthercomprises a pressure regulator having an inlet that receives oxygen fromthe oxygen inlet and having an outlet that supplies oxygen at a lowerpressure. The gas delivery system additionally comprises an anesthesiagas source having an inlet coupled to receive low pressure oxygen fromthe outlet of the pressure regulator and capable of adding anesthesiagas to the low pressure oxygen. The gas delivery system comprises also afirst gas delivery outlet coupled to a gas delivery device that may beplaced in the imaging box interior cavity, the gas delivery devicehaving one or more living specimen interfaces and capable of providinganesthesia gas and oxygen to the one or more living specimen interfaces.The gas delivery system further comprises a second gas delivery outletcoupled to an induction chamber and capable of providing anesthesia gasand oxygen to the induction chamber.

[0011] In yet another aspect, the present invention relates to a gasdelivery device capable of providing anesthesia gas and oxygen tomultiple living specimens. The gas delivery device comprises an inletfor receiving anesthesia gas and oxygen, multiple specimen interfaces,and at least one channel for communicating anesthesia gas and oxygenbetween the inlet and the multiple specimen interfaces. The at least onechannel comprises a buffer volume capable of substantially reducing flowrate fluctuations from the multiple specimen interfaces.

[0012] In still another aspect, the present invention relates to aninduction chamber capable of providing anesthesia gas to a livingspecimen. The induction chamber comprises a set of walls defining aninduction chamber interior. The set of walls include a movable wall thatis movable between an opened condition that enables access to theinterior, and a closed condition that positions the movable wall toprevent access through the opening and that seals the induction chamberinterior from gaseous communication with the environment exterior to theinduction chamber. The induction chamber also comprises a gas inletcapable of receiving anesthesia gas and providing the anesthesia gas tothe interior of the chamber. The induction chamber further comprises ascavenging system comprising a skirt affixed to the set of walls. Theskirt includes a set of holes disposed outside the induction chamberinterior. The set of holes are capable of collecting anesthesia gasoutside the induction chamber when a suitable negative pressure isapplied thereto.

[0013] In another aspect, the present invention relates to an imagingsystem for capturing an image of a living specimen with a camera. Theimaging system comprises an imaging box having a set of walls enclosingan interior cavity and a camera mount configured to position the camerarelative the interior cavity. The imaging system also comprises a gasdelivery system. The gas delivery system includes an oxygen inlet thatreceives oxygen from an oxygen source and an anesthesia gas sourcehaving an inlet coupled to receive oxygen and capable of addinganesthesia gas to the oxygen. The gas delivery system also includes agas delivery outlet coupled to a gas delivery device that may be placedin the imaging box interior cavity. The gas delivery device has one ormore living specimen interfaces and is capable of providing anesthesiagas and oxygen to the one or more living specimen interfaces when in theimaging box interior cavity. The gas delivery device also includes ascavenger system capable of drawing in anesthesia gas output from one ormore of the specimen interfaces. The scavenger system comprises anexhaust port for coupling to a conduit, at least one hole capable ofdrawing in anesthesia gas when a suitable negative pressure is appliedthereto, and at least one channel capable of communicating gases betweenthe at least one hole and the exhaust conduit.

[0014] These and other features of the present invention will bedescribed in more detail below in the detailed description of theinvention and in conjunction with the following figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is illustrated by way of example, and notby way of limitation, in the figures of the accompanying drawings and inwhich like reference numerals refer to similar elements and in which:

[0016]FIG. 1 is a perspective view of an imaging system in accordancewith one embodiment of the present invention.

[0017]FIG. 2 shows an exemplary functional illustration of an anesthesiadelivery system in accordance with one embodiment of the presentinvention.

[0018]FIGS. 3A and 3B illustrate front and rear views, respectively, ofan exemplary anesthesia delivery console in accordance with oneembodiment of the present invention.

[0019]FIG. 4 illustrates an induction chamber in accordance with oneembodiment of the present invention.

[0020]FIG. 5A illustrates a gas delivery device in accordance with oneembodiment of the present invention.

[0021]FIG. 5B illustrates a top cutaway view of the gas delivery deviceof FIG. 5A showing its internal channel taken through the midsection ofeach specimen interface.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] In the following detailed description of the present invention,numerous specific embodiments are set forth in order to provide athorough understanding of the invention. However, as will be apparent tothose skilled in the art, the present invention may be practiced withoutthese specific details or by using alternate elements or processes. Inother instances well known processes, components, and designs have notbeen described in detail so as not to unnecessarily obscure aspects ofthe present invention.

[0023] I. Imaging System

[0024] In one aspect, the present invention relates to imaging systemsfor capturing an image of a low intensity light source. FIG. 1illustrates an imaging system 10 configured to capture photographic andluminescence images in accordance with one embodiment of the presentinvention. Imaging system 10 may be used for imaging a low intensitylight source, such as luminescence from luciferase-expressing cells,fluorescence from fluorescing molecules, and the like. The low intensitylight source may be emitted from any of a variety of light-emittingsamples which may include, for example, animals containinglight-emitting molecules, e.g., various mammalian subjects such as micecontaining luciferase expressing cells.

[0025] Imaging system 10 comprises an imaging box 12 having a door andwalls that define an interior cavity that is adapted to receive alight-emitting sample in which low intensity light, e.g.,luciferase-based luminescence, is to be detected. Imaging box 12 isoften referred to as “light-tight”, e.g., it seals out essentially allof the external light from the ambient room from entering the box 12,and may include one or more seals that prevent light passage into thebox when the door is closed. The seals may also be effective to preventanesthesia gases used within box 12 from escaping into the ambient room.Imaging box 12 is suitable for imaging including the capture of lowintensity light on the order of individual photons, for example.

[0026] Imaging box 12 includes an upper housing 16 adapted to receive acamera. A high sensitivity camera 20, e.g., an intensified or acharge-coupled device (CCD) camera, is mounted on top of upper housing16 and positioned above imaging box 12. CCD camera 20 is capable ofcapturing luminescent and photographic (i.e., reflection based images)images of a sample placed within imaging box 12. CCD camera 20 is cooledby a suitable source such as a refrigeration device 22 that cycles acryogenic fluid through the CCD camera via conduits 24. A suitablerefrigeration device is the “CRYOTIGER” compressor, which can beobtained from IGC-APD Cryogenics Inc., Allentown, Pa. Other methods,such as liquid nitrogen, may be used to cool CCD camera 20.

[0027] Imaging system 10 also includes an anesthesia delivery system(FIGS. 2-5). The anesthesia delivery system includes console 52 (FIGS.3A and 3B), induction chamber 54 (FIG. 4), and a gas delivery device 56(FIGS. 5A and 5B). Gas delivery device 56 may be placed within box 12and includes multiple specimen interfaces for communicating anesthesiagas to one or more living specimens. For example, box 12 typicallyincludes a stage that supports one or more specimens to be imaged, andgas delivery device 56 may be place on the stage in proximity to theliving specimens. Conduit 62 allows gaseous communication between gasdelivery device 56 and console 52. A light-sealed hole 27 is included ina side wall of box 12 to allow a gas conduit 62 to pass therethroughwhile device 56 is in box 12. Conduit 62 may comprise tubing or asuitable hose. For example, ⅜ inch OD ¼ inch ID 90 durometer vitonrubber tubing is suitable for use as conduit 62.

[0028] Oxygen delivery conduit 58, such as a rubber tube or hose, isoperably coupled to an oxygen inlet of main console 52 and an outlet ofan oxygen supply source. For example, the oxygen supply source may be ahigh pressure oxygen cylinder or conventional medium pressure walloutlet. Conduits 60 and 62 are coupled to outlets of main console 52 andcoupled to inlet of induction chamber 54 and gas delivery device 56,respectively.

[0029] An image-processing unit 26 optionally interfaces between camera20 and a computer 28 through cables 30 and 32 respectively. Computer 28,which may be of any suitable type, comprises a main unit 36 thattypically contains hardware including a processor, memory componentssuch as random-access memory (RAM) and read-only memory (ROM), and diskdrive components (e.g., hard drive, CD, floppy drive, etc.). Computer 28also includes a display 38 and input devices such as a keyboard 40 andinput mouse 42. Computer 28 is in communication with various componentsin imaging box 12 via cable 34. To provide communication and control forthese components, computer 28 includes suitable processing hardware andsoftware configured to provide output for controlling any of the devicesin imaging box 12. The processing hardware and software may include anI/O card, control logic for controlling any of the components of imagingsystem 10, and a suitable graphical user interface that facilitates userinteraction with imaging system 10. Components controlled by computer 28may include camera 20, motors responsible for camera 20 focus, motorsresponsible for position control of a platform supporting the livingspecimens, the camera lens, f-stop, etc.

[0030] Computer 28 may also include suitable processing hardware andsoftware for camera 20 such as additional imaging hardware and software,calibration software, and image processing logic for processinginformation obtained by camera 20. The logic in computer 28 may take theform of software, hardware or a combination thereof. Computer 28 alsocommunicates with a display 38 for presenting imaging information to theuser. For example, the display 38 may be a monitor, which presents animage measurement graphical user interface (GUI) that allows a user toview imaging results and also acts an interface to control the imagingsystem 10.

[0031] II. Anesthesia Delivery System

[0032] The present invention employs an anesthesia delivery system thatreliably delivers anesthesia gases and oxygen to multiple gas outlets.FIGS. 2-5 illustrate different components of an anesthesia deliverysystem 50 in accordance with one embodiment of the present invention.

[0033]FIG. 2 shows an exemplary functional illustration of anesthesiadelivery system 50 in accordance with a specific embodiment of thepresent invention. For illustrative purposes, working-pressure oxygenflow arrows 80 and combined anesthesia gas and oxygen flow arrows 84 areprovided to help illustrate the flow of gases through system 50 when allcontrol valves are open and gases flow freely.

[0034] Oxygen delivery conduit 58 is coupled to an oxygen inlet 59 ofconsole 52. Oxygen conduit 58 delivers oxygen at a pressure determinedby the outlet pressure of an oxygen source that conduit 58 is coupledto. For example, if the oxygen source corresponds to a wall supply,oxygen pressure in conduit 58 is typically between about 45 and about 55psi. Alternately, if a pressurized cylinder is used as the oxygensource, oxygen pressure is supplied according to the outlet pressure ofthe tank (up to 2000 psi). Within system 50, oxygen may perform one ormore of the following tasks: act as a carrier for an anesthesia gas,life sustainment for a specimen associated with the anesthesia deliverysystem, a purge gas for induction chamber 54, and a meter for flowmetermeasurement. The oxygen inlet 59 of main console 52 includes oxygenon/off valve 66, which allows a user to turn on/off oxygen provided byconduit 58. Oxygen passed through oxygen on/off valve 66 flows to reliefvalve 63, which limits the pressure seen in system 50 despite the oxygensource outlet pressure. In a specific embodiment, pressure relief valve63 releases from about 55 to about 95 psi, however, it is understoodthat the relief pressure of pressure relief valve 63 may adjustedaccordingly to the requirements of system 50. From relief valve 63,oxygen flows to purge valve 120 and/or pressure regulator 68.

[0035] Pressure regulator 68 includes an inlet that receives oxygen fromoxygen inlet 59. Pressure regulator 68 reduces the pressure of oxygen asreceived at its inlet, and outputs oxygen from a regulator outlet with alower pressure. In one embodiment, pressure regulator 68 outputs oxygenin the range of about 0.5 to about 5 psi gauge. In a specificembodiment, pressure regulator 68 outputs oxygen at about 1 psi gauge. Apressure regulator model number 8286 as provided by Porter Instrumentsof Hatfield, Pa. may be suitable for use as pressure regulator 68.

[0036] Oxygen output from pressure regular 68 travels via conduit 67 tovaporizer 70. Disposed between pressure regulator 68 and vaporizer 70 isa pressure relief valve 72. In some cases, vaporizer 70 may fail if itsees too high a high-pressure. Pressure relief valve 72 thus protectsvaporizer 70 from pressure regulator 68 failure and thereby increasessafety of the anesthesia delivery system 50 by maximizing the allowablepressure encountered by vaporizer 70. In a specific embodiment, pressurerelief valve 72 releases at 5 psi, however, it is understood that therelief pressure of pressure relief valve 72 may adjusted accordingly todesign specifics of vaporizer 70.

[0037] The present invention includes an anesthesia gas source orsimilar device that provides a controllable level of an anesthesia gasor agent. As the term is used herein, an anesthesia gas refers to anygas or agent that is used to induce any level of anesthetic state,unconsciousness, lack of awareness, or local or general insensibility topain for a specimen interacting with gas delivery system 50. Vaporizer70 is an anesthesia gas source that adds an anesthesia gas tolow-pressure oxygen and includes an inlet that receives low-pressureoxygen from an outlet of pressure regulator 68. The output of vaporizer70 typically comprises a controlled and variable gas mixture of lifesustaining gases and anesthetizing gases. In a specific embodiment,vaporizer 70 adds isoflurane to low pressure oxygen received frompressure regulator 68 by passing the oxygen across a vaporizer thatevaporates isoflurane. In this case, the low-pressure oxygen acts as acarrier for the anesthesia gas, which is added to the oxygen accordingto the physical characteristics of the anesthesia liquid and itstemperature. Vaporizer 70 may employ one or more variable bypass, flowover, temperature compensated, and/or agent-specific vaporizationtechniques. Although the present invention will now be described withrespect to vaporizer 70 adding only a single anesthesia gas, isoflurane,it is understood that an anesthesia gas source of the present inventionmay add multiple anesthesia gases, as one of skill in the art willappreciate. A VIP 3100 Calibrated Vaporizor as provided by MDS Matrix ofOrchard Park, N.Y. may be suitable for use as vaporizer 70.

[0038] The output 84 of vaporizer 70 is a combination of low-pressureoxygen and anesthesia gas. Vaporizer 70 includes one or more outputconduits that lead to separate gas delivery outlets, each of which iscapable of providing oxygen and anesthesia gas from console 52. Asshown, console 52 includes two gas delivery outlets: a first gasdelivery outlet 81 for servicing a gas delivery device having specimeninterfaces for communicating gases to one or more living specimens, anda second delivery outlet 71 that services induction chamber 54.

[0039] Console 52 includes an on/off valve, flow control valve andflowmeter for each gas delivery outlet that delivers oxygen andanesthesia gas from console 52. More specifically, a first on/off valve72 allows a user to turn on/off low-pressure oxygen and anesthesia gasprovided by output port 71. Conduit 73 provides gaseous communicationbetween output port 71 and induction chamber 54. Flow control 75 isdisposed between on/off valve 72 and output port 71, and allows a userto variably control and set the flow rate of low-pressure oxygen andanesthesia gas supplied from output port 71. Flowmeter 74 is disposedbefore output port 71 and after flow control 75 and measures the flowrate of gases that pass there through. In one embodiment, flowmeter 74includes a conventional output that visually indicates flowrate to auser. After low-pressure oxygen and anesthesia gas pass through on/offvalve 72, flow control 75, flowmeter 74, and output port 71, the gasesare supplied to induction chamber 54.

[0040] Induction chamber 54 receives low-pressure oxygen and anesthesiagas from conduit 73. Induction chamber 54 allows a user to anesthetize aliving specimen that fits within induction chamber 54, and will bedescribed in further detail with respect to FIG. 4. An exhaust port 132(FIG. 4) is included in the side of induction chamber 54 and is coupledto conduit 77. Exhaust port 132 and conduit 77 withdraw gases frominduction chamber 54 and provide them to filter 78. In one embodiment,filter 78 is a charcoal filter that removes unused isoflurane thatpasses therethrough. A filter model number 80120 F/Air Cannister asprovided by A.M. Bickford of Wales Center, N.Y. is suitable for use asfilter 78. Filter 78 outputs primarily oxygen. As shown, filter 78outputs oxygen into the ambient room.

[0041] Console 52 includes a second outlet that provides oxygen andanesthesia gas supply to gas delivery device 56 (FIG. 5). Morespecifically, on/off valve 82 allows a user to turn on/off low-pressureoxygen and anesthesia gas provided by output port 81. Conduit 62provides gaseous communication between output port 81 and gas deliverydevice 56. Flow control 85 is disposed between on/off valve 82 andoutput port 81, and allows a user to variably control and set the flowrate of low-pressure oxygen and anesthesia gas supplied from output port81. Flowmeter 84 is disposed before output port 81 and after flowcontrol 85 and measures the flow rate of gases that pass therethrough.In one embodiment, flowmeter 84 is a conventional mechanical flowmeter,such as a conventional rotometer, and may comprise one or more of thefollowing components: a needle valve, an indicator float, user controlknobs, and valve stops. In another embodiment, an electronic flowmeteris employed and flow rate is indicated on a monitor screen or similarelectronic output device. After low-pressure oxygen and anesthesia gaspass through on/off valve 82, flow control 85, flowmeter 84, and outputport 81, the gases are supplied to gas delivery device 56.

[0042] Thus, each gas delivery outlet of system 50 comprises its ownflow control. As opposed to conventional anesthesia delivery systems inwhich anesthesia gas delivery is controlled by a general flow controlthat roughly adapts the amount of oxygen received from an oxygen supplysource, disposing a dedicated flow control and flowmeter for each outletaccording to system 50 allows precise and independent control of gasesto induction chamber 54 and gas delivery device 56. In particular,system 50 allows independent and specific control of anesthesia gases toeach outlet—after generation of the anesthesia gas by vaporizer70—thereby allowing a user to variably tailor the amount of anesthesiagas provided to a specimen at any given time. In a specific embodiment,flowmeter 75 comprises a control knob that allows a user to vary flowrate from about 0 L/min to about 5 L/min through outlet port 71. Inanother specific embodiment, flowmeter 85 comprises a control knob thatallows a user to vary flow rate from about 0 L/min to about 2 L/minthrough outlet port 81.

[0043] Gas delivery device 56 receives low-pressure oxygen andanesthesia gas from conduit 62. Gas delivery device 56, which will bedescribed in further detail with respect to FIG. 5, includes a number ofspecimen interfaces, each of which is capable of accommodating a livingspecimen and providing oxygen and anesthesia gas to the specimen. Theanesthesia gas may be used to anesthetize a living specimen, or if thespecimen is already anesthetized—to maintain a desired anesthetic state.

[0044] Anesthesia gas introduced into imaging box 12 via gas deliverydevice 56 may be collected and exhausted to alleviate the buildup ofanesthesia gases in the box. Imaging box 12 includes a sealed exhaustport 86 that allows collected anesthesia gases to be removed from withinimaging box 12. Conduit 95 is coupled on its opposite ends to exhaustport 86 and vacuum port 97, which leads to a vacuum pump 88. Vacuum pump88 applies a negative pressure through conduit 95 sufficient to drawanesthesia gases from within box 12. In one embodiment, vacuum pump 88draws and collects anesthesia gases generally from the box 12 interior.In another embodiment, gas delivery device 56 includes a scavengingsystem that locally removes gases introduced by the specimen interfaceand not used by one or more living specimens (explained in greaterdetail with respect to FIG. 5). Either way, vacuum pump 88 and conduit95 collect unused anesthesia gases from box 12. Flowmeter 91 allows auser to determine the flow rate of gases drawn through vacuum pump 88.In another embodiment, a suitable flow control is employed to allow auser to set the pressure/flow rate of gases drawn by pump 88. Gasescollected by pump 88 are then transmitted to filter 90 through an outletport 98 of console 52. In one embodiment, filter 90 is a charcoal filterthat removes unused isoflurane and outputs primarily oxygen enriched airinto the ambient room.

[0045]FIGS. 3A and 3B illustrate front and back views, respectively, ofconsole 52 in accordance with one embodiment of the present invention.As shown, a housing 101 supports many of the components described withrespect to FIG. 2 as well as numerous other interface mechanisms. Forexample, switch 102 (FIG. 3A) permits control of oxygen on/off valve 66of FIG. 2. Exhaust pump 88 is controlled using pump on/off switch 104,which is disposed beside flowmeter 91. On/off switches and flowmetersare also illustrated for each of the gas outlets. Referring to FIG. 3B,numerous conduits 105 are shown that interconnect many of the functionalcomponents of console 50 and the inlet and outlet ports 59, 69, 71, 81,and 97. In a specific embodiment, ¼ inch OD orbital welded stainlesssteel tubes are used as conduits 105 and are fixed to their respectiveports and components using standard industrial gas fittings.Alternately, ⅜ inch OD 60 durometer viton rubber tubing may be used forconduits with significant bending.

[0046] Having briefly discussed the functional arrangement of anesthesiadelivery system 50 in accordance with one embodiment of the presentinvention, several gas delivery components of the system will now bedescribed in further detail.

[0047] III. Induction Chamber

[0048]FIG. 4 illustrates induction chamber 54 in accordance with oneembodiment of the present invention. Induction chamber 54 allows a userto anesthetize a living specimen that fits within induction chamber 54.As shown, induction chamber 54 includes four vertical walls 122 a-dfixed to a bottom 123. Lid 124 is hingeably coupled to back wall 122 cusing hinges 125 that are fixed to the outer sides of wall 122 c and lid124. Walls 122, bottom 123 and lid 124 define an interior of inductionchamber 54. Lid 124 is movable between an opened condition that definesan opening into chamber 54 and enables access to the interior, and aclosed condition that prevents access to the interior. Seal 127 isdisposed along the inner surfaces of walls 122 and mates with lid 124,when lid 124 is in the closed position, to provide a seal that preventsgaseous communication between the interior of induction chamber 54 andthe environment exterior to induction chamber 54. In a specificembodiment, seal 127 comprises a rubber or silicone seal and walls 122,bottom 123, and lid 124 or all made from a transparent plastic suchpolycarbonate. Using transparent walls for induction chamber 54advantageously allows a user to view the interior of induction chamber54.

[0049] Inlet port 130 is disposed in back wall 122 c and allows gaseouscommunication between the inside and outside of induction chamber 54. Asshown, inlet port 130 receives conduit 60, which provides low-pressureoxygen and anesthesia gas from port 71 of console 52.

[0050] In one embodiment, outlet port 132 is disposed in back wall 122 cand allows gaseous communication between the inside and outside ofinduction chamber 54. As shown, outlet port is coupled to conduit 77,which exhausts gases from induction chamber 54 to filter 78 (FIG. 2). Asshown, anesthesia gases are exhausted from induction chamber 54 based onpositive pressure build up in the interior and relief using conduit 77.In an active removal embodiment, conduit 77 may be associated withnegative pressure via a vacuum pump, such as vacuum pump 88 of FIG. 2,to actively draw gases from induction chamber 54.

[0051] In another embodiment, induction chamber 54 employs a scavengingsystem to collect and exhaust anesthesia gases. After anesthetizing aliving specimen within induction chamber 54, a user typically opens lid124 to move the specimen into imaging box 12. At this point, gases fromwithin the chamber 54 interior—including anesthesia gases—may escapefrom induction chamber 54. Often, the anesthesia gas is denser than airand spills over the side walls 122. To facilitate the capture ofanesthesia gas that escapes from induction chamber 54, the scavengingsystem employed by induction chamber 54 includes holes 138 disposed in askirt 140. The top of skirt 140 is attached to bottom 123. Holes 138 areperipherally disposed about walls 122 and associated with channels (notshown) within skirt 140 that collectively lead to an outlet port, orsimilar interface, that couples to a conduit and vacuum pump 88. Vacuumpump 88 provides a suitable negative pressure that draws gases intoholes 138 and creates a downdraft about the outside of induction chamber54. Thus, anesthesia gases that escape the induction chamber 54 interiormay be collected by holes 138, pass through their associated channels,and flow to the vacuum pump for subsequent filtering. In one embodiment,skirt 140 comprises from about 10 to about 50 holes, each having adiameter of about 0.061 to about 2.54 mm. In a specific embodiment,skirt 140 comprises 17 holes, each having a diameter of about 1.86 mm.

[0052] Inlet port 134 is also disposed in back wall 122 c and allowsgaseous communication between the inside and outside of inductionchamber 54. Inlet port 134 is coupled to conduit 65, which providesworking pressure oxygen communication with purge valve 120. Referringback to FIG. 2, purge valve 120 allows a user to flood induction chamber54 with working pressure oxygen from the regulated supply pressureoxygen source. Flow restricter 122 reduces the flow rate of oxygenprovided by the external oxygen supply before entering induction chamber54. Conduit 65 is coupled to oxygen induction chamber outlet 69 ofconsole 52 and an oxygen inlet port 134 of induction chamber 54.

[0053] In operation, a user opens lid 124 and places a living specimenwithin the interior of induction chamber 54. After closing lid 124, andsealing the interior of induction chamber 54 from the ambient room,oxygen and anesthesia gas are supplied to the interior via console 52and inlet port 130. During this time, exhaust gases may be activelyremoved from induction chamber 54 using a pump or one of the exhausttechniques described above. After anesthesia delivery to the livingspecimen is complete, e.g. when the specimen has been put to sleep, lid124 is opened and the specimen removed. Scavenging exhaust 136 maycollect and exhaust anesthesia gases that escapes induction chamber 54.

[0054] IV. Specimen Interface

[0055] The present invention also relates to a gas delivery device thatis capable of delivering an anesthesia gas and oxygen to multiple livingspecimens. FIG. 5A illustrates a top perspective view of gas deliverydevice 56 of FIG. 1 in accordance with one embodiment of the presentinvention. Gas delivery device 56 is particularly useful for operationin imaging box 12 to maintain the anesthetic state of a specimen inducedby induction chamber 54. Gas delivery device 56 comprises a front face157 having many features suitable for gas interchange with multipleliving specimens. In a specific embodiment, gas delivery device 56 is asolid structure machined from one or more pieces of black anodizedaluminum.

[0056] Gas delivery device 56 comprises an inlet port 152 on one end forcoupling to a conduit that delivers an anesthesia gas and oxygen, suchas conduit 62 from outlet port 81 of console 52. Five specimeninterfaces 156 a-e are horizontally disposed along a front face 157 ofgas delivery device 56. Inlet port 152 opens into a channel 154 (FIG.5B) that substantially spans the length of device 56. FIG. 5Billustrates a top cutaway view of gas delivery device 56 showing channel154 taken through the vertical midsection of each specimen interfaces156. Channel 154 communicates anesthesia gases and oxygen from inletport 152 to each specimen interface 156.

[0057] Channel 154 is larger in cross-sectional area than inlet port 152includes a buffer volume sufficiently large to substantially reduce flowrate inconsistencies and fluctuations to and from the specimeninterfaces 156. In this manner, a large volume of gas accumulated withinchannel 154 may act as a buffer to facilitate substantially constantflow of anesthesia gas and oxygen from interfaces 156 despitefluctuations in the delivery of anesthesia gas and oxygen. In a specificembodiment, channel 154 is circular in cross-section and has a diameterin the range of about 0.15 to about 0.75 inches and a length spanningdevice 56 save the outside walls. In a specific embodiment, channel 154is circular in cross-section and has a diameter of about 0.313 inches.

[0058] In one embodiment, a disposable sleeve is inserted each specimeninterface 156. The disposable sleeve has a smaller orifice at channel154 and a larger orifice distal from channel 154 at front face 157. In aspecific embodiment, the disposable sleeve includes a substantiallyfrustoconical shape that increases in diameter as it extends away fromchannel 154. In operation, the head of a specimen is disposed in, orproximate to, the disposable sleeve. When the disposable sleeve is usedwith a sleeping mouse for example, the head of the mouse may rest on thedisposable sleeve. Since the cross-sectional area that the anesthesiagas encounters increases as it travels through the disposable sleeve,the flow rate of the gas decreases as it approaches the specimen. As aresult, the anesthesia gas may have a more laminar and less turbulentflow from each specimen interface 156.

[0059] Gas delivery device 56 also comprises a scavenger system capableof drawing and collecting waste anesthesia gases. Since the amount ofanesthesia gas supplied usually exceeds the amount necessary for thespecimen, scavenging according to the present invention decreases box 12pollution—and pollution in the surrounding room after the door to box 12is opened.

[0060] As shown, the scavenger exhaust comprises an array of holes 160perimetrically located about each of the specimen interfaces 156. Holes160 locally draw and collect anesthesia gas when a suitable negativepressure is applied thereto. An exhaust port 161 acts as an exterioroutlet from gas delivery device 56 and allows external attachment to aconduit. A longitudinal channel (not shown) allows gaseous communicationbetween exhaust port 161 and each of the holes 160. The longitudinalchannel runs the face 157 length of gas delivery device 56 from exhaustport 161 to the opposite end. Internal channels (not shown) extendwithin gas delivery device 56 between each of the holes 160 and thelongitudinal channel. In one embodiment, a conduit connected to exhaustport 161 actively draws gases through holes 160, through theirassociated internal channels, through the longitudinal channel, andthrough exhaust port 161 using a negative pressure, e.g. via a pump suchas pump 88. Holes 160 are particularly useful for drawing in anesthesiagas output towards a specimen by the specimen interfaces 156. In oneembodiment, oxygen and anesthesia gases flow from each specimeninterface 156 is supplied in a laminar and substantially non-turbulentmanner. Holes 161 may then locally draw anesthesia gas in a minimallyturbulent manner; thereby minimizing gas escape into imaging box 12.

[0061] In another embodiment, holes 162 are also disposed in the uppersurface of gas delivery device 56 to capture anesthesia gas not locallycaptured by holes 161 and to capture anesthesia gas above gas deliverydevice 56. Internal channels (also not shown) extend from holes 162downward towards the longitudinal channel and deliver collected gases toexhaust port 161.

[0062] When imaging is performed on multiple living specimens using gasdelivery device 56, it may be desirable to prevent light emitted by onespecimen from reaching an adjacent specimen. To this end, gas deliveryinterface also includes a vertical slot 164 disposed between each of theadjacent specimen interfaces 156. Each vertical slot 164 is capable ofreceiving and vertically holding a light barrier, such as a paper orotherwise suitable opaque barrier. In a specific embodiment, eachvertical slot 164 is between 0.03 and 0.04 inches thick and penetrates ¼inch into face 157.

[0063] While this invention has been described in terms of severalpreferred embodiments, there are alterations, permutations, andequivalents which fall within the scope of this invention which havebeen omitted for brevity's sake. For example, although gas deliverydevice 56 is described as a solid structure machined from aluminum, itis understood that other designs may the structure of the gas deliverydevice and include tube and bellows systems that equally deliveranesthesia gas to multiple living specimens. It is therefore intendedthat the scope of the invention should be determined with reference tothe appended claims.

What is claimed is:
 1. A gas delivery system capable of delivering ananesthesia gas to a plurality of gas outlets, the system comprising: anoxygen inlet that receives oxygen from an oxygen source; a pressureregulator having an inlet that receives oxygen from the oxygen inlet andhaving an outlet that provides oxygen at a lower pressure; an anesthesiagas source having an inlet coupled to receive low pressure oxygen fromthe outlet of the pressure regulator and capable of adding anesthesiagas to the low pressure oxygen; a first gas delivery outlet coupled to agas delivery device having one or more living specimen interfaces andcapable of providing anesthesia gas and oxygen to the one or more livingspecimen interfaces; and a second gas delivery outlet coupled to aninduction chamber and capable of providing anesthesia gas and oxygen tothe induction chamber.
 2. The gas delivery system of claim 1 wherein thefirst gas delivery outlet comprises an outlet port and a first flowcontrol disposed between the anesthesia gas source and the outlet port.3. The gas delivery system of claim 2 wherein the second gas deliveryoutlet comprises an outlet port and a second flow control disposedbetween the anesthesia gas source and the outlet port.
 4. The gasdelivery system of claim 3 wherein the first and second flow controleach allow independent control of gases to the first gas delivery outletand to the second gas delivery outlet.
 5. The gas delivery system ofclaim 4 wherein the first flow control allows control of gases fromabout 0 L/min to about 5 L/min to the first gas delivery outlet.
 6. Thegas delivery system of claim 1 wherein the induction chamber furthercomprises a gas scavenging system that collects anesthesia gas andoxygen that escapes from the induction chamber interior.
 7. The gasdelivery system of claim 6 wherein the scavenging system includes a setof holes disposed on a skirt attached to the bottom of the inductionchamber, the set of holes in gaseous communication with an exhaustconduit, the set of holes capable of collecting anesthesia gas outsidethe induction chamber when a suitable negative pressure is appliedthereto.
 8. The gas delivery system of claim 7 wherein the set of holesare peripherally disposed about the induction chamber.
 9. The gasdelivery system of claim 1 further comprising a purge inlet capable ofproviding oxygen to the induction chamber interior.
 10. The gas deliverysystem of claim 1 wherein the gas delivery device further comprises aninlet for receiving anesthesia gas and oxygen and at least one channelfor communicating anesthesia gas and oxygen between the inlet and theone or more specimen interfaces.
 11. The gas delivery system of claim 10wherein the at least one channel comprises a buffer volume sufficientlylarge to substantially reduce flow rate fluctuations from the multiplespecimen interfaces.
 12. The gas delivery system of claim 10 furthercomprising a disposable sleeve inserted within a specimen interface, thedisposable sleeve having a smaller orifice at the at least one channeland a larger orifice distal from the at least one channel.
 13. The gasdelivery system of claim 1 wherein each of the one or more livingspecimen interfaces includes multiple specimen interfaces that provide asubstantially equal flow relative to each other.
 14. An imaging systemfor capturing an image of a living specimen with a camera, the systemcomprising: an imaging box having a set of walls enclosing an interiorcavity and a camera mount configured to position the camera relative theinterior cavity; and a gas delivery system comprising; an oxygen inletthat receives oxygen from an oxygen source; a pressure regulator havingan inlet that receives oxygen from the oxygen inlet and having an outletthat provides oxygen at a lower pressure; an anesthesia gas sourcehaving an inlet coupled to receive low pressure oxygen from the outletof the pressure regulator and capable of adding anesthesia gas to thelow pressure oxygen; a first gas delivery outlet coupled to a gasdelivery device that may be placed in the imaging box interior cavity,the gas delivery device having one or more living specimen interfacesand capable of providing anesthesia gas and oxygen to the one or moreliving specimen interfaces when in the imaging box interior cavity; anda second gas delivery outlet coupled to an induction chamber and capableof providing anesthesia gas and oxygen to the induction chamber.
 15. Theimaging system of claim 14 wherein the first gas delivery outletcomprises an outlet port and a first flow control disposed between theanesthesia gas source and the outlet port.
 16. The imaging system ofclaim 15 wherein the second gas delivery outlet comprises an outlet portand a second flow control disposed between the anesthesia gas source andthe outlet port.
 17. The imaging system of claim 16 wherein the firstand second flow control each allow independent flow control of gases tothe first gas delivery outlet and to the second gas delivery outlet. 18.The imaging system of claim 17 wherein the first flow control allowscontrol of gases from about 0 L/min to about 5 L/min to the first gasdelivery outlet.
 19. The gas delivery system of claim 14 wherein theinduction chamber further comprises a gas scavenging system thatcollects anesthesia gas and oxygen that escape from the inductionchamber interior.
 20. The gas delivery system of claim 14 furthercomprising a purge inlet capable of providing oxygen to the inductionchamber interior.
 21. The gas delivery system of claim 14 wherein thegas delivery device further comprises an inlet for receiving anesthesiagas and oxygen and at least one channel for communicating anesthesia gasand oxygen between the inlet and the one or more specimen interfaces.22. The gas delivery system of claim 21 wherein the at least one channelcomprises a buffer volume sufficiently large to substantially reduceflow rate fluctuations from the multiple specimen interfaces.
 23. A gasdelivery device capable of providing anesthesia gas and oxygen tomultiple living specimens, the gas delivery device comprising an inletfor receiving anesthesia gas and oxygen, multiple specimen interfaces,and at least one channel for communicating anesthesia gas and oxygenbetween the inlet and the multiple specimen interfaces, wherein the atleast one channel comprises a buffer volume sufficiently large tosubstantially reduce flow rate fluctuations to the multiple specimeninterfaces.
 24. The gas delivery device of claim 23 further comprising adisposable sleeve inserted within a specimen interface, the disposablesleeve having a smaller orifice at the at least one channel and a largerorifice distal from the at least one channel.
 25. The gas deliverydevice of claim 24 wherein the disposable sleeve is frustoconical. 26.The gas delivery device of claim 23 wherein the channel substantiallyspans the length of the gas delivery device.
 27. The gas delivery deviceof claim 23 further comprising a vertical slot disposed between twoadjacent specimen interfaces, wherein the vertical slot is capable ofreceiving and holding a light barrier.
 28. The gas delivery device ofclaim 23 further comprising a scavenger system capable of drawing inanesthesia gas output from one or more of the specimen interfaces, thescavenger system comprising: an exhaust port for coupling to a conduit;at least one hole capable of drawing in anesthesia gas when a suitablenegative pressure is applied thereto; and at least one channel capableof communicating gases between the at least one hole and the exhaustconduit.
 29. The gas delivery device of claim 28 wherein the scavengersystem comprises an array of holes perimetrically disposed about one ofthe specimen interfaces.
 30. The gas delivery system of claim 23 whereineach of the one or more living specimen interfaces includes multiplespecimen interfaces that provide a substantially equal flow relative toeach other.
 31. An induction chamber capable of providing anesthesia gasto a living specimen, the induction chamber comprising: a set of wallsdefining an induction chamber interior, the set of walls including amovable wall that is movable between an opened condition that enablesaccess to the interior, and a closed condition that positions themovable wall to prevent access through an opening and that seals theinduction chamber interior from gaseous communication with theenvironment exterior to the induction chamber; a gas inlet capable ofreceiving anesthesia gas and providing the anesthesia gas to theinterior of the chamber; and a scavenging system comprising a skirtaffixed to the set of walls, the skirt including a set of holes disposedoutside the induction chamber interior, the set of holes capable ofcollecting anesthesia gas outside the induction chamber when a suitablenegative pressure is applied thereto.
 32. The induction chamber of claim31 wherein the movable wall is a top lid.
 33. The induction chamber ofclaim 31 further comprising an exhaust port capable of collecting gasfrom within the interior of the chamber through one of the inductionchamber walls when a suitable negative pressure is applied thereto. 34.The induction chamber of claim 31 further comprising a set of collectingchannels in gaseous communication with the set of holes and an exhaustconduit in gaseous communication with the set of collecting channels.35. The induction chamber of claim 34 wherein the set of holes areperipherally disposed about the induction chamber.
 36. The inductionchamber of claim 34 wherein the skirt is attached to the bottom of theset of walls.
 37. The induction chamber of claim 31 further comprising apurge inlet capable of providing oxygen to the induction chamberinterior.
 38. An imaging system for capturing an image of a livingspecimen with a camera, the system comprising: an imaging box having aset of walls enclosing an interior cavity and a camera mount configuredto position the camera relative the interior cavity; and a gas deliverysystem including; an oxygen inlet that receives oxygen from an oxygensource; an anesthesia gas source having an inlet coupled to receiveoxygen and capable of adding anesthesia gas to the oxygen; and a gasdelivery outlet coupled to a gas delivery device that may be placed inthe imaging box interior cavity, the gas delivery device having one ormore living specimen interfaces and capable of providing anesthesia gasand oxygen to the one or more living specimen interfaces when in theimaging box interior cavity, the gas delivery device also including ascavenger system capable of drawing in anesthesia gas output from one ormore of the specimen interfaces, the scavenger system comprising anexhaust port for coupling to a conduit, at least one hole capable ofdrawing in anesthesia gas when a suitable negative pressure is appliedthereto, and at least one channel capable of communicating gases betweenthe at least one hole and the exhaust conduit.